Other improvements you may notice in this release (compared to
LibSpiro 20071029) are:
1) LibSpiro tries harder to create curves before giving-up on the
really hard curves.
2) 2+2 enhanced functions which return "pass/fail". Backwards
compatibility is maintained for older programs using older method.
3) code optimizations so that some numbers aren't re-computed
inside loops and routines (summary, should run a little faster).
4) A few error checks, such as making sure memory is allocated,
otherwise fail gracefully and avoid crashes.
5) Checks for inifinte values are done, so that user code doesn't
need to test for this now (LibSpiro returns fail).
6) configure now has options that were only accessible in code
earlier, such as VERBOSE, UNITTEST.
7) 'make check' allows you to test this new LibSpiro before you do
a 'make install'
8) tests/call-test.c includes example code that may help developers
who are interested in creating programs that use LibSpiro.

Other improvements you may notice in this release (compared to
LibSpiro 20071029) are:
1) LibSpiro tries harder to create curves before giving-up on the
really hard curves.
2) 2+2 enhanced functions which return "pass/fail". Backwards
compatibility is maintained for older programs using older method.
3) code optimizations so that some numbers aren't re-computed
inside loops and routines (summary, should run a little faster).
4) A few error checks, such as making sure memory is allocated,
otherwise fail gracefully and avoid crashes.
5) Checks for inifinte values are done, so that user code doesn't
need to test for this now (LibSpiro returns fail).
6) configure now has options that were only accessible in code
earlier, such as VERBOSE, UNITTEST.
7) 'make check' allows you to test this new LibSpiro before you do
a 'make install'
8) tests/call-test.c includes example code that may help developers
who are interested in creating programs that use LibSpiro.

Re: Announcing LibSpiro - version libspiro_beta.0.3.20150131

..then FontForge will correctly "autostop" building (with an error message)
if it does not find libspiro and the related developer h files.

In the meantime, let the distros do what they do best, and let's not
introduce another layer of complexity to the distro maintainers by
packaging duplicate libraries. Give them time to adapt accordingly.